1. Field of the Invention
This invention relates to a tape-end detecting device suitable for a cassette-type tape recorder etc., and more particularly to an improvement in the tape-end detecting device which is capable of suppressing wow and flutter for the tape recorder etc.
2. Description of the Prior Art
In general, a tape-end detecting device incorporated in a cassette-type tape recorder etc. is so constructed that it can detect a stop of rotation of a reel turntable when a tape is fully taken up by either of the reels so as to automatically throw, by a detection output, a tape recorder mechanism into a suspended state.
FIG. 1 illustrates one example of a conventional tape-end detecting device. In the figure, a reel turntable 1 rotates clockwise or counterclockwise when a tape runs and the rotation of the reel turntable 1 rotates a magnet member 3 through a belt 2. The magnet member 3 is fixed to a lower face of a pulley 5 rotatably supported by a shaft 4. The magnet member 3 is magnetized circumferentially in N-poles and S-poles alternatingly. A magnetic sensor element 6 is disposed in the vicinity of the magnet member 3 and generates an output which varies according to variations in a magnetic field produced by the magnet member 3 in response to the rotation of the reel turntable 1. Thus, a tape end can be detected.
This conventional device, however, has disadvantages, in that undesirable wow and flutter is increased and a magnetic loss is enlarged due to attraction between a chassis made of an iron plate and the magnet member 3 because they are located in close proximity to each other.
In addition, the belt 2, shaft 4 and the pulley 5 are needed to rotatably support the magnet member 3. Thus, there have been problems in cost and space.